If you're arguing for separate rules for inviable pregnancies as opposed to life-of-the-mother, sure. That makes sense: there is zero reason to continue with an inviable pregnancy (except, I guess, in the very rare cases where it's medically advisable for the mother). And it seems that, bizarrely, some states do not have robust exemptions for an inviable fetus--Texas, for instance, seems like it would recapitulate Savita's case exactly.

However, if you're using this as an example of how prioritizing the life of the mother isn't enough, no: this shows that in practice the exception was only triggered with far too grave of a threat to the life of the mother--when waiting for the threat to be that bad, you can't always save the mother even if you try.

Rather than saying "so therefore all abortions must be legal", what the example shows is that "therefore the the life of the mother must be prioritized starting with a lesser risk than in cases like that". One way to do that would be to make all abortions legal. But it's not the only way.